regexp_matches question

On Sep 4, 2012, at 21:39, Sergio Basurto <sbasurto@soft-gator.com> wrote:

I am using regexp_matches in a function like this

create or replace function test (v_string in text) returns varchar as $$
declare
i_strings text[];
i_string text[];

i_strings := regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');

You can store a single array value into i_strings. It does not magically convert a multi-row result into an array. You can use ARRAY_AGG to do so or execute the query directly as part of the loop while using a "record" variable to store the current row's value(s).

-- Then I use the results
foreach i_string slice 1 in array i_strings
loop
raise notice 'row = %',i_string;
end loop;

when I run the function like this:

select test('1:Warehouse1;2:Warehouse2;');

postgresql complains:
ERROR: query "SELECT regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g')" returned more than one row

Why postgres is sending the ERROR?

Off course I am expecting more than one row!, that's why is in a foreach loop in the first place.

If I run:
select regexp_matches('1:Warehouse1;2:Warehouse2;',E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');
regexp_matches
----------------
{1:Warehouse1}
{2:Warehouse2}
(2 rows)

I am doing something wrong?

Note that because you do not use grouping in your expression there is only a single array "cell" in each row - but there could be more than one in which case your for-each above would effectively loop through each sub-component of the match.

Regards,

David J.

On Tue, 2012-09-04 at 21:58 -0400, David Johnston wrote:

On Sep 4, 2012, at 21:39, Sergio Basurto <sbasurto@soft-gator.com> wrote:

I am using regexp_matches in a function like this

create or replace function test (v_string in text) returns varchar as $$
declare
i_strings text[];
i_string text[];

i_strings := regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');

You can store a single array value into i_strings. It does not magically convert a multi-row result into an array. You can use ARRAY_AGG to do so or execute the query directly as part of the loop while using a "record" variable to store the current row's value(s).

-- Then I use the results
foreach i_string slice 1 in array i_strings
loop
raise notice 'row = %',i_string;
end loop;

when I run the function like this:

select test('1:Warehouse1;2:Warehouse2;');

postgresql complains:
ERROR: query "SELECT regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g')" returned more than one row

Why postgres is sending the ERROR?

Off course I am expecting more than one row!, that's why is in a foreach loop in the first place.

If I run:
select regexp_matches('1:Warehouse1;2:Warehouse2;',E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');
regexp_matches
----------------
{1:Warehouse1}
{2:Warehouse2}
(2 rows)

I am doing something wrong?

Note that because you do not use grouping in your expression there is only a single array "cell" in each row - but there could be more than one in which case your for-each above would effectively loop through each sub-component of the match.

Regards,

David J.

Thanks for your response David, but my doubt arise because if I use this

i_strings text[] := array [[1:Warehouse1],[2:Warehouse2]];

loops without problem. Is not the same thing?

it prints:

NOTICE: row = {1:Warehouse1}
NOTICE: row = {2:Warehouse2}

On Sep 5, 2012, at 19:02, Sergio Basurto <sbasurto@soft-gator.com> wrote:

On Tue, 2012-09-04 at 21:58 -0400, David Johnston wrote:

On Sep 4, 2012, at 21:39, Sergio Basurto <sbasurto@soft-gator.com> wrote:

I am using regexp_matches in a function like this

create or replace function test (v_string in text) returns varchar as $$
declare
i_strings text[];
i_string text[];

i_strings := regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');

You can store a single array value into i_strings. It does not magically convert a multi-row result into an array. You can use ARRAY_AGG to do so or execute the query directly as part of the loop while using a "record" variable to store the current row's value(s).

-- Then I use the results
foreach i_string slice 1 in array i_strings
loop
raise notice 'row = %',i_string;
end loop;

when I run the function like this:

select test('1:Warehouse1;2:Warehouse2;');

postgresql complains:
ERROR: query "SELECT regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g')" returned more than one row

Why postgres is sending the ERROR?

Off course I am expecting more than one row!, that's why is in a foreach loop in the first place.

If I run:
select regexp_matches('1:Warehouse1;2:Warehouse2;',E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');
regexp_matches
----------------
{1:Warehouse1}
{2:Warehouse2}
(2 rows)

I am doing something wrong?

Note that because you do not use grouping in your expression there is only a single array "cell" in each row - but there could be more than one in which case your for-each above would effectively loop through each sub-component of the match.

Regards,

David J.

Thanks for your response David, but my doubt arise because if I use this

i_strings text[] := array [[1:Warehouse1],[2:Warehouse2]];

loops without problem. Is not the same thing?

it prints:

NOTICE: row = {1:Warehouse1}
NOTICE: row = {2:Warehouse2}

A 2-dimensional array is not the same as a set of 1-dimensional arrays.

David J.

On Wed, 2012-09-05 at 21:15 -0400, David Johnston wrote:

On Sep 5, 2012, at 19:02, Sergio Basurto <sbasurto@soft-gator.com>
wrote:

On Tue, 2012-09-04 at 21:58 -0400, David Johnston wrote:

On Sep 4, 2012, at 21:39, Sergio Basurto <sbasurto@soft-gator.com> wrote:

I am using regexp_matches in a function like this

create or replace function test (v_string in text) returns varchar as $$
declare
i_strings text[];
i_string text[];

i_strings := regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');

You can store a single array value into i_strings. It does not magically convert a multi-row result into an array. You can use ARRAY_AGG to do so or execute the query directly as part of the loop while using a "record" variable to store the current row's value(s).

-- Then I use the results
foreach i_string slice 1 in array i_strings
loop
raise notice 'row = %',i_string;
end loop;

when I run the function like this:

select test('1:Warehouse1;2:Warehouse2;');

postgresql complains:
ERROR: query "SELECT regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g')" returned more than one row

Why postgres is sending the ERROR?

Off course I am expecting more than one row!, that's why is in a foreach loop in the first place.

If I run:
select regexp_matches('1:Warehouse1;2:Warehouse2;',E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');
regexp_matches
----------------
{1:Warehouse1}
{2:Warehouse2}
(2 rows)

I am doing something wrong?

Note that because you do not use grouping in your expression there is only a single array "cell" in each row - but there could be more than one in which case your for-each above would effectively loop through each sub-component of the match.

Regards,

David J.

Thanks for your response David, but my doubt arise because if I use
this

i_strings text[] := array [[1:Warehouse1],[2:Warehouse2]];

loops without problem. Is not the same thing?

it prints:

NOTICE: row = {1:Warehouse1}
NOTICE: row = {2:Warehouse2}

A 2-dimensional array is not the same as a set of 1-dimensional
arrays.

David J.

Thank you David for all your help,

I got it finally thanks your explanation, so the code that works for me
is:

create or replace function test (v_string in text) returns varchar
as $$
declare
i_strings refcursor := null;
i_string text[];
i_query text;

begin

i_query := 'select regexp_matches('''||v_string||''',E''[a-zA-Z0-9:\
\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+'',''g'')';
open i_strings for execute i_query;

if i_strings is not null then
loop fetch i_strings into i_string;
exit when not found;
raise notice 'row =
%',i_string;
end loop;
close i_strings;
end if;
return 0;
end;
$$ LANGUAGE plpgsql;

Thanks again David.

Kind Regards,

On Tue, 2012-09-04 at 21:58 -0400, David Johnston wrote:

On Sep 4, 2012, at 21:39, Sergio Basurto <sbasurto@soft-gator.com> wrote:

I am using regexp_matches in a function like this

create or replace function test (v_string in text) returns varchar as $$
declare
i_strings text[];
i_string text[];

i_strings := regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');

You can store a single array value into i_strings. It does not magically convert a multi-row result into an array. You can use ARRAY_AGG to do so or execute the query directly as part of the loop while using a "record" variable to store the current row's value(s).

-- Then I use the results
foreach i_string slice 1 in array i_strings
loop
raise notice 'row = %',i_string;
end loop;

when I run the function like this:

select test('1:Warehouse1;2:Warehouse2;');

postgresql complains:
ERROR: query "SELECT regexp_matches(v_string,E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g')" returned more than one row

Why postgres is sending the ERROR?

Off course I am expecting more than one row!, that's why is in a foreach loop in the first place.

If I run:
select regexp_matches('1:Warehouse1;2:Warehouse2;',E'[a-zA-Z0-9:\\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+','g');
regexp_matches
----------------
{1:Warehouse1}
{2:Warehouse2}
(2 rows)

I am doing something wrong?

Note that because you do not use grouping in your expression there is only a single array "cell" in each row - but there could be more than one in which case your for-each above would effectively loop through each sub-component of the match.

Regards,

David J.

Thank you David for all your help,

I got it working finally thanks to your explanation, so the code that
works for me is:

create or replace function test (v_string in text) returns varchar
as $$
declare
i_strings refcursor := null;
i_string text[];
i_query text;

begin

i_query := 'select regexp_matches('''||v_string||''',E''[a-zA-Z0-9:\
\s\\-\\.#%]*:[A-Za-z0-9\\s\\-\\.#%]+'',''g'')';
open i_strings for execute i_query;
if i_strings is not null then
loop fetch i_strings into i_string;
exit when not found;
raise notice 'row =
%',i_string;
end loop;
close i_strings;
end if;
return 0;
end;
$$ LANGUAGE plpgsql;

Thanks again David.

Kind Regards,